1. Field of the Invention
The present invention relates generally to a latch system for a fireplace door and, more particularly, to a door latch which will permit a door of a gas-fired fireplace to open and relieve an explosion in the fireplace in the event of an accidental failure of the fireplace ignition system.
2. Description of the Prior Art
Factory-built fireplace assemblies have long been available as both free-standing and wall recessed units. One popular form of a fireplace functions as a room heater and comprises a combustion chamber surrounded by an enclosure providing a passageway for circulating room air over the combustion chamber. Heated air may thereby be circulated into the room either by gravity or by use of a blower system. This type of fireplace is preferably fired with natural or LP gas and has ceramic or cement artificial logs simulating the appearance of a wood burning fireplace while offering the advantage of efficiently converting the natural or LP gas to room heat.
A common design of a gas-fired fireplace is of a construction known as the direct-vent type. In this construction, the combustion chamber is fabricated as a sealed enclosure and is vented by a concentric pipe arrangement in which flue gases are exhausted through a central pipe while intake air is drawn into the combustion chamber through an annular space defined by an outer larger diameter pipe. Such a fireplace construction has become popular because the cooling effect on the central exhaust pipe by the intake air allows the fireplace to be vented without costly masonry chimney construction. Accordingly, the direct-vent, gas-fired fireplace has gained wide acceptance in modern building architecture.
In a standard design of the direct-vent, gas-fired fireplace, the combustion chamber is sealed at its front face by a glass panel. The glass panel serves to enclose the combustion chamber while allowing the fire to be viewed by the occupants of the room. However, a failure in the ignition system of the fireplace could cause excess accumulation of gas within the combustion chamber which, if ignited, could in turn cause a combustion chamber explosion. Such an explosion could pose a safety hazard to the room occupants if the glass fireplace front were to shatter. Accordingly, it is common in fireplace design to use explosion relief panels in the metal enclosure of the combustion chamber. These panels are essentially designed to blow out under the pressure of an explosion and relieve the combustion chamber pressure without breaking the glass front.
A disadvantage of present fireplace construction using explosion relief panels in the combustion chamber is that in the event the panels are blown out by an explosion, it is a very labor-intensive job to repair the fireplace. Particularly, in typical cases in which the fireplace is a wall-recessed unit, the entire fireplace must be disassembled and removed from the wall to gain access to the relief panels. Generally, another disadvantage of common fireplace construction is that the frontal glass panel is mechanically secured to the fireplace enclosure by screws and other hardware making it time consuming to gain access to the interior of the enclosure in the event that maintenance of the fireplace needs to be performed.
Accordingly, it is desirable to provide a fireplace assembly in which explosion relief panels need not be constructed in the combustion chamber to relieve internal pressure from a possible gas explosion. It is further desirable to provide a fireplace assembly in which the typical front glass panel is readily removable, without the need for tools of any kind when access to the interior of the fireplace is necessary.